[nativepaul]

Don't kid yourself that its low power just because its a small motor.

A motor will draw as many amps as it needs to to pull the gearing you have at the speed its KV and voltage determine, a bigger motor just has more thermal mass to heat up slower and more surface area for better heat disipation, a 7XL will handle more power than a 7L for extended periods while keeping cool enough for a long service life due to the aforementioned better cooling. The 7L and 7xl have the same number of turns, and the same diameter rotors and cans, making it very likely that they both have the same gauge wire making up the windings, if we look at short term power capability the windings will fuse at the same amp draw and the same voltage is on both so the are capable of the same absolute power.

The 7L is 3511kv which on 4s is about 50,000RPM, a 7XL is 2382kv which is about 33,350RPM, so if the gearing is the same the 7L will be pulling a lot more power than the 7XL in order to spin the extra speed. As gears get rather inefficient at 11teeth and under so if I assume you use a 12t pinion with typical buggy 3.3:1 diff ratios and 4.5" tyres, it is geared for 50 mph (+any ballooning) and pulling more than average amps to do so (most buggy racers seem to gear for about 40mph depending on the track), a 7XL in the same buggy would be up to an 18 tooth pinion before it is making the same power as the 7L.

Torque is not only related to the size, magnets, pole count and KV of the motor but to the current flowing through it, while a huge low KV motor like the 1717 will have a much higher KT than than the 7L, .86oz-in/A vs .39oz-in/A if the little 7l is screaming its guts out on 4s about to melt it will have MANY more Amps flowing though it than a 1717 running cool on 6s and could be producing dogbone breaking torque.

A 7L is not really suited to 4s, you would be better off on 3s with a 13tooth pinion which would give you 40mph, cooler running, and less breakages. if you want to stick with 4s I would recommend a motor with a much lower KV (somewhere in the 2000 range), and though I have several, I wouldn't recommend a Feiago nowadays, Leopards are a fair bit more efficient for not much more money.